RE: Remington Mod. 798
The 798 is a really nice gun- you won't be sorry with that purchase. The .243 should do the job for everything you mentioned, though it is a little on the light side for black bears. I'd use a 55 - 75 grain bullet for coyotes, a 90 - 100 grain bullet for deer, and a 100 grain premium bullet (i.e. Nosler, Barnes, etc.) for black bear. I wouldn't try angling, difficult shots on black bears. If you wait until you have a good standing broadside shot, put it behind the shoulder and it should do the job. You may need a follow-up shot sometimes, depending on how big the bear is.